RC Snubber Circuit Design for ITER PF Converter Module

The proper RC snubber circuit is of great importance to protect the thyristor against overvoltage during the turn-off process. This paper mainly presents the design of commutating over-voltage RC snubber circuit for ITER poloidal field (PF) converter module. Based on the reverse recovery transient model of the multi-parallel thyristors and commutating overvoltage circuit model, the RC snubber parameters of PF converter module are obtained by the detailed theoretical calculations, and then the simulation analysis and the commutating overvoltage test of the prototype are done to verify the RC snubber components selection, the simulation and test results show that the design of RC snubber circuit can meet the commutating overvoltage protection requirement.